1. Field of the Invention
The present invention relates to a portable terminal such as a cellular phone, and more particularly, to a method of inputting a function into a portable terminal by using a plurality of buttons of the portable terminal, and a button input apparatus using the same.
2. Description of Related Art
In general, a user of a portable terminal can select functions thereof, such as making/receiving a phone call and transmitting/receiving a short message, and inputting Korean characters, English characters, and numerals using a plurality of buttons on a side of the portable terminal.
Recently, portable terminals, such as cellular phones, provide not only conventional main functions, such as a phone call function and a short message function, but also functions of other electronic devices. For example, various functions, such as an MP3 file play function, an image capture and reproduction function, an electronic dictionary function, and/or a digital TV function are available in cellular phones.
An increase of the kinds of functions of cellular phones results in an increase of the number of devices for controlling the functions. However, many users expect that these integrated functions will not increase the complexity of using the portable terminal, and the size and price thereof compared to conventional portable terminals.
Although it is not so difficult to integrate various functions into a portable terminal or miniaturize the portable terminal, there are many technical problems to be addressed in order to provide an interface to allow a user to input complex functions and control the portable terminal quickly and easily. For example, the development of a user interface to reduce the number of key inputs performed by a user for a specific function or easily manage, search, and reproduce various kinds of digital content, such as photographs, moving pictures, music, and e-mail, has been required.
Furthermore, the increase of the number of buttons for inputting various functions, is limited by the device size and the complexity of using a larger number of buttons.
In addition, since the complexity of using the portable terminal increases, it is very difficult for a user to memorize button inputs and a button input sequence corresponding to every necessary function, and thus, an undesired function may be executed due to a wrong button input.